Update 2.deploy-connect-dashboard-ent.md (#1298)

* Update 2.deploy-connect-dashboard-ent.md

* Update 2.deploy-connect-dashboard-ent.md

docs-2.0/nebula-dashboard-ent/2.deploy-connect-dashboard-ent.md

@@ -17,6 +17,7 @@ Before deploying Dashboard Enterprise Edition, you must do a check of these:
   | 9090 | The port of the prometheus service. |
   | 9200 | The port of the nebula-stats-exporter service. |
   | 9093 | The port of the Alertmanager service, used to receive Prometheus alerts and then send them to Dashboard.|
+  | 9100   | The port of the node-exporter service. The node-exporter is aumatically deployed on the target machine after a cluster is created or imported. It is used to collect the source information of machines in the cluster, including the CPU, memory, load, disk, and network.   |
 
 - The license is ready.